High-temperature pressure sensor and production method thereof

Abstract

The invention belongs to the technical field of pressure sensors, particularly relates to a high-temperature pressure sensor and a production method thereof and solves the problem that the existing pressure sensor fails to operate normally in environments of high temperature, moistness and the like due to the insufficiently reasonable design. The high-temperature pressure sensor comprises four layers. A planar square spiral inductor and a capacitor upper electrode are made on the first layer by pasting; a sealed pressure cavity is arranged on the second layer; a capacitor electrode is made on the fourth layer by pasting and is connected with an inner circular core of the top planar square spiral inductor. The production method includes filling the pressure cavity with carbon paste; subjecting the laminated structure to high-temperature sintering to volatilize carbon from air holes so as to form a complete cavity; and after sintering, placing glass beads at the air holes to allow for secondary sintering sealing. The high-temperature pressure sensor is capable of operating at normal temperature and high temperature more than 400 DEG C, and is simple in structure, small in size, simple in manufacture process and easy for industrial production.

Description

technical field [0001] The invention belongs to the technical field of pressure sensors, and in particular relates to a high-temperature pressure sensor and a preparation method thereof. Background technique [0002] At present, it is still difficult for pressure sensors with MEMS structures in the world to perform stable measurements in environments above 400 °C. The impact of high temperature environment makes the pressure sensitive structure fail or the temperature noise makes the pressure signal unable to be transmitted. For some common piezoresistive pressure sensors, due to the need to supply power to the bridge and detect the voltage, it is difficult to guarantee the stability of the electrical leads connecting the bridge and the detection circuit in a high temperature environment. On the one hand, when the ambient temperature exceeds 400 °C, due to the interdiffusion of metal and semiconductor, the ohmic contact between the lead wire and the varistor will change irr...

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Problems solved by technology

[0003] The present invention aims at the difficulties of MEMS sensors in the above realistic high-temperature and harsh environment, solves the problem that the current pressure sensor cannot work normally in the high-temperature and high-pressure environment, and provides a passive high-temperature pressure sensor based on LTCC ceramics that can work in a high-temperature airflow environment. Sensor and its preparation method, which can work above 400 ° C without providing power

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